Gets regExpItems.
[:alnum:]=any character of [:digit:] or [:alpha:] class
[:alpha:]=any letter.
[:blank:]=space or tab.
[:cntrl:]=any character with octal codes 000 through 037, or DEL (octal code 177).
[:digit:]=any digit.
[:graph:]=any character that is not a [:alnum:] or [:punct:] class.
[:lower:]=any lower case letter.
[:print:]=any character from the [:space:] class, and any character that is not in the [:graph:] class.
[:punct:]=any one of ! \" # $ % & ' ( ) * + , - . / : ; < = > ?